Preheat your oven to 400°F and line a large sheet pan with parchment paper for easy cleanup.
Cut the chicken breast into 1-inch bite-sized pieces and halve the baby potatoes so they cook evenly.
In a large mixing bowl, whisk together the extra virgin olive oil, lemon juice, dried oregano, garlic powder, sea salt, and black pepper.
Add the chicken pieces, halved potatoes, broccoli florets, and sliced red bell pepper to the bowl, tossing thoroughly to coat everything in the lemon-herb mixture.
Spread the ingredients in a single layer across the prepared sheet pan, ensuring they are not overcrowded so the vegetables can roast rather than steam.
Place the pan in the oven and roast for 20 to 25 minutes, or until the chicken is cooked through and the potatoes are fork-tender and golden brown.
Remove from the oven and serve immediately while the chicken is juicy and the vegetables are perfectly crisp-tender.